I would assume you would have to choose GPU bifurcation from BIOS (just find whatever iGFX settings there is and set it so that it enables you to run integrated while there is dedicated GPU installed, so it does not disable it). Probably though, you would be better of using only one GPU and if you planned on using 5600G, why not just get AMD GPU, because they likely work better together in this kind of setting where you try to use both iGPU and dGPU.
https://www.techspot.com/review/2505-geforce-rtx-3050-vs-radeon-6600/ 6600 would also have been both cheaper and clearly faster.